The company, set up by Chief Executive Peter Cruddas as a foreign exchange broker with a 10,000 pound investment in 1989, said net operating income and revenue per client in the six months ending Sept. 30 were higher than a year earlier.

Active contracts for differences (CFDs) and spreadbet clients for the period were slightly lower than a year earlier, which saw a boost following the short-term interest seen around Britain’s vote to leave the European Union, CMC said.

“The firm remains cautious about the future outlook given the ongoing regulatory uncertainty and the impact, if any, potential changes could have on Group performance,” CMC said in a statement on Thursday.

CFDs allow investors to bet on moves in share prices without having to buy the underlying stock. However, regulators have been tightening controls on the fast-growing 3.5 billion pound ($4.70 billion) spreadbetting industry.

CMC, which rivals IG Group , Denmark’s Saxo Bank and Global Brokerage Inc, said costs would rise in the second half of the year, driven higher by marketing initiatives and the roll out of its stockbroking partnership with ANZ Bank .